1. Field of the Invention
This invention relates to polyalkoxysilylalkylenedisilazanes and polyalkoxysilylalkylenesilylamines and their use to produce polyalkoxysilyl terminated polydiorganosiloxanes in which the terminal group is bonded to the polymer through an alkylene linkage.
2. Background Information
U.S. Pat. No. 3,175,993, issued Mar. 30, 1965 teaches organopolysiloxanes which are endblocked with alkoxylated silcarbane groups. The compositions are prepared by reacting a hydrogen endblocked siloxane with an alkoxylated aliphatic silane in the presence of a platinum catalyst, or by reacting an aliphatic endblocked siloxane with an alkoxylated silane in the presence of a platinum catalyst. The use of the product in producing sealants is also taught.
U.S. Pat. No. 4,395,526 issued July 26 1983 teaches one package moisture curable polyalkoxy-terminated organopolysiloxane compositions having a condensation catalyst. The composition can be made using a silanol terminated polydiorganosiloxane and a silane scavenger. U.S. Pat. No. 4,515,932, issued May 7, 1985 teaches a novel end-capping catalyst for such materials.
West German Pat. No. 3,524,484, issued July 7, 1985, teaches the condensation of linear organopolysiloxanes containing SiOH groups in the presence of phosphorus nitride chloride catalyst, and the reaction with hexaorganodisilazane to give an organopolysiloxane with triorganosiloxy end groups.
U.S. Pat. No. 4,599,394, issued Jul 8, 1986 teaches reacting a silanol-terminated polydiorganosiloxane or vinyl-terminated polydiorganosiloxane with a hydrogen-containing polyalkoxysilane in the presence of a platinum catalyst. The resulting alkoxy-terminated polydiorganosiloxane can be used to produce RTV silicone rubber compositions.
A method of producing silicone elastomeric sealants of the type using a polyalkoxy-terminated polymer, crosslinker, and titanium catalyst with improved shelf life is taught in U.S. Pat. No. 4,652,624. issued Mar. 24, 1987. The shelf life is improved by adding a polyalkoxy-terminated polymer which has the terminal silicon bonded to the next silicon through a divalent hydrocarbon radical.